require 'digest/sha1'

class User < ActiveRecord::Base
	validates_presence_of	:name
	validates_uniqueness_of	:name
	
	attr_accessor	:password_confirmation
	validates_confirmation_of	:password
	
	def validate
		errors.add_to_base("Missing password") if hashed_password.blank?
	end

	def self.authenticate(name, password)
		user = self.find_by_name(name)
		if user
			expected_password = encrypted_password(password,user.salt)
			if user.hashed_password != expected_password
				user = nil
			else
        return user
      end
		end
	end
	
	def password
		@password
	end
	
	def password=(pwd)
		@password = pwd
		return if pwd.blank?
		create_new_salt
		self.hashed_password = User.encrypted_password(self.password, self.salt)
	end
	
	private 
	
	def self.encrypted_password(password,salt)
		string_to_hash = password + "Wibble" + salt
    Digest::SHA1.hexdigest(string_to_hash)
	end
	
	def create_new_salt
		self.salt = self.object_id.to_s + rand.to_s
	end
  
  def after_destory
    if User.count.zero?
      raise "Can't delete last user"
    end
  end
end